1. Field of the Invention
The present invention relates to a tooth structure of a rotary saw blade particularly used for cutting hard and brittle material such as glass, precious stones, tiles and bricks and to a method of forming the tooth structure.
2. Description of the Prior Art
A typical prior art saw blade design is shown in FIGS. 8 and 9. As shown therein, the rotary saw blade includes a disc-like base plate 1 and a plurality of teeth 2 formed on the peripheral portion of the base plate 1. The teeth 2 are spaced apart from each other by a predetermined pitch in a circumferential direction. On the entire surface of each of the teeth 2, diamond grains 3 of about No. 120 U.S. mesh are electrically deposited so as to form a toothed portion 4.
However, in the above conventional construction of the toothed portion, diamond grains 3a are deposited on the top surface 2a of each tooth 2 to cut a work. Therefore, as is apparent from the characteristic line b shown in FIG. 12, the cutting performance of the diamond grains 3a gradually degrades as they are worn.
Consequently, as shown in FIG. 12, the cutting performance is considerably degraded in the case that the diamond grains 3a have been worn out and the top surfaces of the toothed portion 4 become flat and smooth.
Thus, in the conventional construction, the diameter of the diamond grain is relatively small, and the state of wear of the diamond grains 3a cannot be recognized by visual observation. Further, the duration of life of the rotary saw blade is difficult to be recognized since its cutting performance gradually degrades. Therefore, the conventional construction has the drawbacks in that the users tend to miss the time of exchange or to misunderstand the blade for a defective one.
The above drawbacks are important factors for traders who rent such rotary saw blades.